The invention relates to a foaming apparatus in accordance with the introductory portion of patent claim 1.
During filling of liquid filling material that can develop a foam (particularly carbon dioxide containing beverages) and, particularly preferred, during filling of beer, it is known to displace the remaining air volume that is present after a corresponding container has been filled, with displacing being done with such a development of foam of the liquid filling material, prior to closing, so as to avoid impairment of the taste and the stability of the filled liquid filling material by the influx of air or, respectively, oxygen.
For foam development of the liquid filling material or, respectively, for displacing the remaining air volume in containers that are filled with the filling material, but not yet closed, such containers are conveyed, on a conveyor with connects the filling machine and a container closing apparatus, beneath a nozzle apparatus that has at least one nozzle. A predetermined volume of the foam developing medium, preferably in the form of a liquid is respectively introduced from this nozzle apparatus into the corresponding containers, such that the liquid filling material filled into the container is induced to develop foam and that by way of the foamxe2x80x94increasingly arising from the filling materialxe2x80x94there is removed, by way of displacement, the remaining quantity of air from the container. For an optimal foam development it is desired in the art to achieve that the foam of the filling material or, respectively, the crown of foam provided thereby, is then reaching the upper mouth of the container or, respectively, reaches slightly beyond this container upper mouth, but without foam overflowing, or substantial over-foaming, when the corresponding container reaches the closing position of the container closing apparatus. The closing position is thereby that position of the container at which is secured a closure element or, respectively, the corresponding container is sealed.
A too strong or particularly strong foam development or, respectively, foam overflowing from the container, which causes losses of filling material and contamination of the container closing apparatus, is to be avoided; as is a too little foam developmentxe2x80x94which leads to an insufficient displacement of the remaining air volume from the corresponding container. The extent of foam development or, respectively, the foam development at the closing position, is a function, inter alia, of that period of time which is available for the foam development, that is, between the introduction of the medium to develop foam into a container and the closing. This also means that the extent of foam development is a function of the velocity of the conveyor and, accordingly, a function of the plant""s capacity (processed bottles per unit time).
Since the extent of foam development is also a function of the type of the corresponding filling material, that is, of the foam development capability of the liquid filling material, in connection of a liquid foam development machine it has already been proposed (DExe2x80x94OS 16 32 034) to adjust that pressure that is produced by a pneumatic pressure booster, that is, a piston pump arrangement actuated by compressed air, of the liquid foam developing material, in conformity with the corresponding filling material and, more particularly, by adjustment of the pressure of the compressed air which is used to power the pressure booster.
It is the object of the invention to achieve a further improvement at those foam developing apparatus with which improvement there will be avoided an additional intake of oxygen during the injection process.
The invention teaches that this object can be accomplished by a foam developing apparatus configured with the characterizing feature of patent claim 1.
In the foam developing apparatus in accordance with the invention a further reduction of the oxygen uptake is achieved by a partial or sufficient protective gas space at the level above the mouths of the bottles passing by, whereby the foam developing medium, comprised mostly of water, is injected through the protective gas space into the bottle.
In this manner there are avoided the otherwise unavoidable inclusions of surrounding air during the injection process.
Further features of the invention are the subject of the dependent claims.